The present invention relates to an electric sauna heater and to control and safety means therefor.
An electric sauna heater includes control and safety means which can include one or more relays (e.g. temperature or current controlled) for switching power to the heating elements of the sauna heater, a thermostat (mechanical or electronic) for controlling the relay(s), a temperature limiter to disconnect power from the heating elements in the event of excessive temperature in the sauna room, sensor elements for the thermostat and temperature limiter, and operating controls for connecting and disconnecting power manually and/or by means of a timer and for setting the operating temperature desired.
Certain elements of the control and safety means for the sauna heater, specifically the relay(s) which switch power to the heating elements, cannot, due to present electric safety requirements, be installed in the sauna room as a separate unit from the heater unit which includes the heating elements. Consistent with such present safety requirements, the control and safety means of the sauna heater are being installed in any of the following manners.
1. A separate control center which includes the relay(s), thermostat, temperature limiter and the operating controls is positioned outside the sauna room with the sensor elements of the thermostat and the temperature limiter being brought into the sauna room from the control center.
2. A separate control center which includes the relay(s) and the operating controls is positioned outside the sauna room and a separate combination of a thermostat and a temperature limiter and the sensors thereof are positioned in the suana room.
3. The entire control and safety means except for the sensor elements of the thermostat and temperature limiter are installed in the same unit as the heating elements, i.e., in the heater unit, with the sensor elements of the thermostat and of the temperature limiter being led to the wall of the sauna room from the common heater unit.
The third alternative, of which a plurality of variations is possible, is the least expensive. However, all such variations are cumbersome and difficult to use and some may even be hazardous to users. Where the operating controls (e.g. knobs for setting the timer and the thermostat) are located in the lower portion of the heater unit, operation of those controls and reading of the scales of those controls are difficult because it is necessary for the person performing these operations to bend nearly down to floor level. If the operating controls are located in the upper portion of the heater or above it, the person operating the controls runs the risk of burning himself on the hot sauna stones (which can be at temperatures of 400.degree. C. to 500.degree. C.